The general strategy for this study is provided by the hypothesis that behavior is the joint product of hereditary and environmental influences: that behavior is a phenotype. The proposed experiments deal with: (a) phenotypic characterization of behavior, through identification of simple behavioral units in the early approach preferences of the Japanese quail (C. coturnix japonica) and separation of random from systematic variations in their manifestation; (b) examination of the mediating mechanisms implicated in naive approach preferences, through experimental manipulations and identification of those genetic, environmental, and interactive genetic-and-environmental influences which are responsible for systematic individual variations in their manifest expression; (c) examination of the sources of individual variation in the processing and coding of information pertinent to environmental modification of early approach preferences, and to the related long term behavioral developments, through identification of those genetic, environmental, and interactive genetic-and-environmental factors which are responsible for individual variations in learning associated with preferences; and (d) identification of species-general units, processes, and morphological correlates of behavioral-information-code, through abstraction of mediative units of information in the sources of individual variations specified in points b and c above and examination of their morphological correlates in the specific genotypic, neurophysiological, and neurochemical mechanisms of individual organisms. Similar to the concentration of early genetic investigations (which paved the way to the identification of the genetic-information-code) on the Drosophila, the proposed research concentrates on the Japanese quail (C. coturnix japonica) and its early approach preferences because of the particular promise of this species and phenomena for basic, species-general data on behavioral information code, and because of the practical suitability of this species and behaviors for population analyses, phenotypic characterization, genetic and experiential manipulation, and morphological examination. Early approach preferences of the quail lend themselves exceptionally well to examinations of how hereditary factors may result in critical sensitivities and canalizing tendencies in early life, how such sensitivities and tendencies interact with environmental input, and what are the basic processes of morphological mediation in the interaction of identifiable genetic and experiential influences. It is our hope that the proposed examination of such mechanisms and processes in relation to simple units of stimulus-information and well defined patterns of individual variation in the related early choice responses of the quail will pave the way to the understanding of the units and mechanisms of a species-general information code pertinent to the expression of behavior, including, ultimately, the morphological identification of such units and mechanisms.